linux/drivers/media/video/cx23885/cx23885-i2c.c
Jean Delvare a824f0f445 [media] video: Drop undue references to i2c-algo-bit
There's one comment that has been copied from bttv to many other
media/video drivers:

/* init + register i2c algo-bit adapter */

Meanwhile, many drivers use hardware I2C implementations instead of
relying on i2c-algo-bit, so this comment is misleading. Remove the
reference to "algo-bit" from all drivers, to avoid any confusion. This
is the best way to ensure that the comments won't go out of sync
again. Anyone interested in the implementation details would rather
look at the code itself.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-11-24 15:11:17 -02:00

403 lines
9.6 KiB
C

/*
* Driver for the Conexant CX23885 PCIe bridge
*
* Copyright (c) 2006 Steven Toth <stoth@linuxtv.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
*
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/io.h>
#include "cx23885.h"
#include <media/v4l2-common.h>
static unsigned int i2c_debug;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
static unsigned int i2c_scan;
module_param(i2c_scan, int, 0444);
MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
#define dprintk(level, fmt, arg...)\
do { if (i2c_debug >= level)\
printk(KERN_DEBUG "%s/0: " fmt, dev->name, ## arg);\
} while (0)
#define I2C_WAIT_DELAY 32
#define I2C_WAIT_RETRY 64
#define I2C_EXTEND (1 << 3)
#define I2C_NOSTOP (1 << 4)
static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
{
struct cx23885_i2c *bus = i2c_adap->algo_data;
struct cx23885_dev *dev = bus->dev;
return cx_read(bus->reg_stat) & 0x01;
}
static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
{
struct cx23885_i2c *bus = i2c_adap->algo_data;
struct cx23885_dev *dev = bus->dev;
return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
}
static int i2c_wait_done(struct i2c_adapter *i2c_adap)
{
int count;
for (count = 0; count < I2C_WAIT_RETRY; count++) {
if (!i2c_is_busy(i2c_adap))
break;
udelay(I2C_WAIT_DELAY);
}
if (I2C_WAIT_RETRY == count)
return 0;
return 1;
}
static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
const struct i2c_msg *msg, int joined_rlen)
{
struct cx23885_i2c *bus = i2c_adap->algo_data;
struct cx23885_dev *dev = bus->dev;
u32 wdata, addr, ctrl;
int retval, cnt;
if (joined_rlen)
dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
msg->len, joined_rlen);
else
dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
/* Deal with i2c probe functions with zero payload */
if (msg->len == 0) {
cx_write(bus->reg_addr, msg->addr << 25);
cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
if (!i2c_wait_done(i2c_adap))
return -EIO;
if (!i2c_slave_did_ack(i2c_adap))
return -ENXIO;
dprintk(1, "%s() returns 0\n", __func__);
return 0;
}
/* dev, reg + first byte */
addr = (msg->addr << 25) | msg->buf[0];
wdata = msg->buf[0];
ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
if (msg->len > 1)
ctrl |= I2C_NOSTOP | I2C_EXTEND;
else if (joined_rlen)
ctrl |= I2C_NOSTOP;
cx_write(bus->reg_addr, addr);
cx_write(bus->reg_wdata, wdata);
cx_write(bus->reg_ctrl, ctrl);
if (!i2c_wait_done(i2c_adap))
goto eio;
if (i2c_debug) {
printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
if (!(ctrl & I2C_NOSTOP))
printk(" >\n");
}
for (cnt = 1; cnt < msg->len; cnt++) {
/* following bytes */
wdata = msg->buf[cnt];
ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
if (cnt < msg->len - 1)
ctrl |= I2C_NOSTOP | I2C_EXTEND;
else if (joined_rlen)
ctrl |= I2C_NOSTOP;
cx_write(bus->reg_addr, addr);
cx_write(bus->reg_wdata, wdata);
cx_write(bus->reg_ctrl, ctrl);
if (!i2c_wait_done(i2c_adap))
goto eio;
if (i2c_debug) {
dprintk(1, " %02x", msg->buf[cnt]);
if (!(ctrl & I2C_NOSTOP))
dprintk(1, " >\n");
}
}
return msg->len;
eio:
retval = -EIO;
if (i2c_debug)
printk(KERN_ERR " ERR: %d\n", retval);
return retval;
}
static int i2c_readbytes(struct i2c_adapter *i2c_adap,
const struct i2c_msg *msg, int joined)
{
struct cx23885_i2c *bus = i2c_adap->algo_data;
struct cx23885_dev *dev = bus->dev;
u32 ctrl, cnt;
int retval;
if (i2c_debug && !joined)
dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
/* Deal with i2c probe functions with zero payload */
if (msg->len == 0) {
cx_write(bus->reg_addr, msg->addr << 25);
cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
if (!i2c_wait_done(i2c_adap))
return -EIO;
if (!i2c_slave_did_ack(i2c_adap))
return -ENXIO;
dprintk(1, "%s() returns 0\n", __func__);
return 0;
}
if (i2c_debug) {
if (joined)
dprintk(1, " R");
else
dprintk(1, " <R %02x", (msg->addr << 1) + 1);
}
for (cnt = 0; cnt < msg->len; cnt++) {
ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
if (cnt < msg->len - 1)
ctrl |= I2C_NOSTOP | I2C_EXTEND;
cx_write(bus->reg_addr, msg->addr << 25);
cx_write(bus->reg_ctrl, ctrl);
if (!i2c_wait_done(i2c_adap))
goto eio;
msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
if (i2c_debug) {
dprintk(1, " %02x", msg->buf[cnt]);
if (!(ctrl & I2C_NOSTOP))
dprintk(1, " >\n");
}
}
return msg->len;
eio:
retval = -EIO;
if (i2c_debug)
printk(KERN_ERR " ERR: %d\n", retval);
return retval;
}
static int i2c_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg *msgs, int num)
{
struct cx23885_i2c *bus = i2c_adap->algo_data;
struct cx23885_dev *dev = bus->dev;
int i, retval = 0;
dprintk(1, "%s(num = %d)\n", __func__, num);
for (i = 0 ; i < num; i++) {
dprintk(1, "%s(num = %d) addr = 0x%02x len = 0x%x\n",
__func__, num, msgs[i].addr, msgs[i].len);
if (msgs[i].flags & I2C_M_RD) {
/* read */
retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
msgs[i].addr == msgs[i + 1].addr) {
/* write then read from same address */
retval = i2c_sendbytes(i2c_adap, &msgs[i],
msgs[i + 1].len);
if (retval < 0)
goto err;
i++;
retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
} else {
/* write */
retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
}
if (retval < 0)
goto err;
}
return num;
err:
return retval;
}
static u32 cx23885_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
}
static struct i2c_algorithm cx23885_i2c_algo_template = {
.master_xfer = i2c_xfer,
.functionality = cx23885_functionality,
};
/* ----------------------------------------------------------------------- */
static struct i2c_adapter cx23885_i2c_adap_template = {
.name = "cx23885",
.owner = THIS_MODULE,
.algo = &cx23885_i2c_algo_template,
};
static struct i2c_client cx23885_i2c_client_template = {
.name = "cx23885 internal",
};
static char *i2c_devs[128] = {
[0x10 >> 1] = "tda10048",
[0x12 >> 1] = "dib7000pc",
[0x1c >> 1] = "lgdt3303",
[0x86 >> 1] = "tda9887",
[0x32 >> 1] = "cx24227",
[0x88 >> 1] = "cx25837",
[0x84 >> 1] = "tda8295",
[0x98 >> 1] = "flatiron",
[0xa0 >> 1] = "eeprom",
[0xc0 >> 1] = "tuner/mt2131/tda8275",
[0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
[0xc8 >> 1] = "tuner/xc3028L",
};
static void do_i2c_scan(char *name, struct i2c_client *c)
{
unsigned char buf;
int i, rc;
for (i = 0; i < 128; i++) {
c->addr = i;
rc = i2c_master_recv(c, &buf, 0);
if (rc < 0)
continue;
printk(KERN_INFO "%s: i2c scan: found device @ 0x%x [%s]\n",
name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
}
}
/* init + register i2c adapter */
int cx23885_i2c_register(struct cx23885_i2c *bus)
{
struct cx23885_dev *dev = bus->dev;
dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
memcpy(&bus->i2c_adap, &cx23885_i2c_adap_template,
sizeof(bus->i2c_adap));
memcpy(&bus->i2c_algo, &cx23885_i2c_algo_template,
sizeof(bus->i2c_algo));
memcpy(&bus->i2c_client, &cx23885_i2c_client_template,
sizeof(bus->i2c_client));
bus->i2c_adap.dev.parent = &dev->pci->dev;
strlcpy(bus->i2c_adap.name, bus->dev->name,
sizeof(bus->i2c_adap.name));
bus->i2c_algo.data = bus;
bus->i2c_adap.algo_data = bus;
i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
i2c_add_adapter(&bus->i2c_adap);
bus->i2c_client.adapter = &bus->i2c_adap;
if (0 == bus->i2c_rc) {
dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
if (i2c_scan) {
printk(KERN_INFO "%s: scan bus %d:\n",
dev->name, bus->nr);
do_i2c_scan(dev->name, &bus->i2c_client);
}
} else
printk(KERN_WARNING "%s: i2c bus %d register FAILED\n",
dev->name, bus->nr);
/* Instantiate the IR receiver device, if present */
if (0 == bus->i2c_rc) {
struct i2c_board_info info;
const unsigned short addr_list[] = {
0x6b, I2C_CLIENT_END
};
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
/* Use quick read command for probe, some IR chips don't
* support writes */
i2c_new_probed_device(&bus->i2c_adap, &info, addr_list,
i2c_probe_func_quick_read);
}
return bus->i2c_rc;
}
int cx23885_i2c_unregister(struct cx23885_i2c *bus)
{
i2c_del_adapter(&bus->i2c_adap);
return 0;
}
void cx23885_av_clk(struct cx23885_dev *dev, int enable)
{
/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
char buffer[3];
struct i2c_msg msg;
dprintk(1, "%s(enabled = %d)\n", __func__, enable);
/* Register 0x144 */
buffer[0] = 0x01;
buffer[1] = 0x44;
if (enable == 1)
buffer[2] = 0x05;
else
buffer[2] = 0x00;
msg.addr = 0x44;
msg.flags = I2C_M_TEN;
msg.len = 3;
msg.buf = buffer;
i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
}
/* ----------------------------------------------------------------------- */
/*
* Local variables:
* c-basic-offset: 8
* End:
*/